Fuel exhaustion engine failure in a Continental PA46

As most know, I love the Continental-Powered Malibu, but today I had my first true engine failure in a Malibu (the other was in a Lycoming-powered Mirage about a decade ago).  Bottom line (to ease the drama of the unknown)…all is well…the airplane is fine…I’m fine…and no insurance company will be contacted.  It was a good ending to a bad flight, but it still scared the crap out of me.  Here’s the story…

It was a short flight in East Texas, but one that was full of challenges.   There were a bunch of showers and small thunderstorms in the area, and I ended up flying below the bases and avoided the shafts.  The light bumps were incessant and there was an occasional bolt of lightning in the distance.

Takeoff was normal, but the climb out was different.  I noticed the CHT on 3 of the cylinders was climbing fast.  I was climbing through about 4,500MSL when I first noticed the higher CHT’s.  The highest CHT was 413F when I started to get serious about discovering what was wrong (and I REALLY try to keep the CHT’s below 375F!).  I next noticed that the full-throttle (35″MP) fuel flow was only 33gph (it’s normally around 37gph). Quickly I decided to reduce the throttle, stay low (below the cloud bases), and see what would happen with a lesser power setting.

I pulled the throttle back to 30″MP, prop to 2400 RPM, and reduced the mixture to 50 degrees LOP.  All of the numbers looked right (CHT came down FAST, OP/OT were in the green, and cruise speed normal).  I continued flying to the airport, but cautiously…with plenty of showers around to divert my attention.

About 5 miles from the airport, the engine coughed noticeably, and then returned to a steady hum.  It sounded like a “Continental Cough”, much like when the mixture is set too lean.  I enriched the mixture slightly and continued the descent to the runway.  As the runway loomed larger and larger in the windscreen, I set up for a normal approach and landing.  At about 50 feet I reduced the throttle to idle near the landing flare and the engine simply died.  I was over the runway, so it was not dramatic, but it did occur.

I started the engine again on the runway during rollout, and it died almost as soon as it started.  I started it again and this time noticed that the engine ran when I pushed the PRIME switch (bringing the fuel pump to HIGH for short periods).  As I taxied off the runway, the engine would die whenever I was not depressing the PRIME switch.  So, I turned the fuel pump switch to LOW.  The engine would not run on LOW.  I pushed the PRIME switch sporadically on the VERY short taxi to the parking spot on the ramp.

As I pulled into the parking spot, the ground-guideman pointed at my nose and gave facial gestures that convinced me he saw something unusual.  I quickly shut the engine down and jumped out of the airplane.  As I moved to the front of the airplane, there was still fuel spilling out of the front.  There were blue streaks along the landing gear, belly, and nose gear doors.  Clearly, there was a big fuel leak.

I had the Malibu towed to the maintenance hangar and with the cowl removed it took only a few seconds to determine the problem.  The main fuel line that passes through the engine baffling has a threaded fitting (some call it a “B” Fitting).  This fitting had blue stains all over it, and it could be turned with the fingers…it was super-loose.  A quick  turn of the fitting with a wrench and the fitting was tight again.

I called some of my favorite PA46 experts and all confirmed the serious threat that befallen me.  As it turned out, the vacuum pump had been replaced recently and the fuel line needed to be removed to access the fuel pump.  In this case, the fuel lines were installed but not torqued correctly.  It was an easy omission, but a potentially deadly omission. (For anyone that is wondering…I did talk with the maintenance facility that replaced the pump, and that mechanic was super-apologetic and used this experience as a teaching tool to shore up the Quality Control at that shop.  And…I assure you that I will NOT make the name of this shop public-domain…it was a simple mistake from a really good shop that is getting better.)

Looking back, I was SUPER-fortunate.  The fuel-starved engine gave up power at an ideal place in flight…had it been any earlier, I would have had an off-airport landing event.  But…and here’s the lesson to be learned…the engine DID give me a clue that something was not right.  Looking back, the high CHT’s and the low climb fuel-flow should have alarmed me greatly.  The cylinders simply did not have the normal amount of fuel, and in climb the additional fuel is used for cooling.  Case in point…if your engine shows any “abnormal behavior”, treat it like there’s a real problem…because there is a problem.

And…one more thing…when I used the PRIME switch and the LOW Pump, I was pressurizing a fuel leak.  One spark, one drop of fuel on the super-hot turbos, just about anything could have started a fire that I would have been pressurized with fuel.  There’s many times in my aviation career that I’ve felt I survived “but by the grace of God”, and this time was one of those times.  This day could have been so much worse!  Had the failure happened in flight, I’m sure I would have reached for the PRIME switch, and that might have started the engine, but I could have experienced an in-flight fire, which is almost always deadly.

I’ll look back on this day with a strong appreciation for a better preflight, a better reaction to when the airplane “whispers” to me that things are “not quite right”, and a hopeful appreciation to our Lord for providing.

About Joe Casey

ATP, CFI, CFII, MEI, CFI-G Commercial Pilot - SE, ME, Rotorcraft, Glider US Army AH-64 Pilot and UH-60 Instructor Pilot and Instrument Flight Examiner
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